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This may have been discussed before, but I need to know the effects of enlarging or reducing the size of the soundhole. I'm building a smallbody, so it probably will need some help in the bass dept. Do I enlarge or reduce? What other effects should I expect when adjusting sound hole size?

Thanks

Al

reduce...

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
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Thanks...Thats what I was thinking but i wanted to be sure before cutting wood. I'm thinking reduce the radius by about 1/8" from my usuall 2"?

AlA Peebels38813.8799537037

That seams very aggressive there Al

going from 4" to 3-3/4" is a large reduction I think.

Maybe other would jump in here, On my 000 size I go 3-7/8", maybe it just doesn't matter that much.

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3-7/8" is good, yes.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

3-7/8" it will be. Thanks    Al

won't reducing the radius by 1/8" actually reduce the size of the soundhole by 1/4".

I realize that there is "new math" and all , but I think you want to reduce it 1/16" if you want the final dimension to be 3 7/8"

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Yes Brock I was going to reduce it to 3-3/4" but with a little help from my friends decided to reduce it to 3-7/8"

Al

I do my OM and 000 guitars with 3.77" but I find my 00 guitar needs a larger soundhole, 4.125" or more and then my largest guitar requires a 4". It depends on so many things. You say you are building a small body guitar Al, how small? what body shape are you doing? the shape of the guitar (body size, depth etc) make a big difference on soundhole size, and then you have folks like Mario who use large soundholes for everything (I think that is correct is it not Mario) On my first L-00 I started with a 3.77" soundhole and enlarged it and discovered when it got to about 4.125" it sounded best, smaller it had a muddy sound, larger it lost it's punch.

[QUOTE=Brock Poling]
won't reducing the radius by 1/8" actually reduce the size of the soundhole by 1/4".[/QUOTE]

Funnily enough, increasing the radius by 1/8" (say for example the width of a 1/8" spiral downcut bit) also increases the size of the soundhole by 1/4". Don't ask me how I know this

Arvey it's a tad smaller than my Taylor 612 same basic shape

Al

Course I have no idea what a taylor 612 is so I can't help you much, Maybe use your Taylor as a starting point. Relationship between size and depth comes into play as well. Better to go a little small and if you arn't happy increase the size of the hole. If you want to play with trying a smaller hole you can do a bound soundhole and see how that changes the sound.

Why not make it a bit small, with a larger than usual margin, and then you can enlarge it if you have to? It's not too bad using a marking gauge to enlarge the hole by a bit and keep it neat.

For some good general information, look up William Allen's articles on air modes in American Lutherie; particularly the one in AL#1. Obviuosly, that's in the first 'Red Book'. The rules of thumb are:
1) Bigger hole, higher 'main air' resonance, and
2) The farther from the middle of the length of the guitar (closer to the edge) the lower the pitch,
3) Bigger hole= more sound.

There also seems to be some effect with the high-end 'cuttoff frequency' of the soundhole, so that a larger hole seems to be 'brighter', but there are other things that are tricky to sort out from that. In fact, the whole hole thing is tricky enough that you're better off usually to alow for some fudge factor the first time out with a new design, and trim it up to get what you want.

Thanks everyone.

Al

According to what i've just read here, i'm wondering if 4" is considered as a large soundhole for dreadnaughts? 4" is what i'll be doing on the next 2 guitars, is it too big or can i even cut a bit bigger?

Serge: I've been using 4" on my slopes, and dreds. Not to say that is the best size, it's just what I've been doing.
My interest is based on a smaller design that I am building.

Al

Is it also true that less or lighter bracing for smaller size instruments will also help in the bass department?


Wade

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Wade
Nashua, NH
http://www.wadefx.com

Thanks Al! i'll be staying with diameter then!

Wade S:
A lot of things can help the bass, but there's no free lunch. Each of them has other effects, and some of those might be things you don't want.

Moving the hole is a good example. Shifting it up toward the upper edge may 'help the bass' by dropping the 'main air' pitch, but it might also make the tone more uneven because that air resonance is not reinforcing notes between it's own pitch and the 'main top' resonance at around the open G. Making the 'main air' pitch too low, say, as low as the low E, is not usually a good thing for that reason.

Reducing the top brace sizes will drop the pitch of the 'main top' resonance, all else equal, and this will usually make the bass tone stronger. However, you can lose some of the 'sparkle' from the high end, as the higher-order resonan modes are also dropped in pitch. In the extreme the tone could end up tubby, and temporary. The braces, of course, are your first line of defence against the dreaded 'folding top syndrome'. And so it goes.

That little phrase 'all else equal' covers an encyclopedia of stuff, of course. You could talk about thinning the top, 'tuning' the back, 'tuning' the 'neck mode', the effect of different woods, such as cedar on the top or rosewood vs mahogany B&S, 'graduating' the top thinner toward the tailblock, making the sides deeper, reducing soundhole size, a heavier bridge, heavier strings.... That's a pretty good sample of things that all can 'improve' the bass, and probably far from exhaustive.   

After a while you learn some of the effects that different things have, and this gives you some ways to shape the sound by 'tweaking' different elements. You also, of course, have to learn what the limits are, and that can entail a few failures of more or less disasterous sorts. Goes with the turf.